Re: A89: Starting out assembly, need help

[Prev][Next][Index][Thread]

Re: A89: Starting out assembly, need help

To: assembly-89@lists.ticalc.org
Subject: Re: A89: Starting out assembly, need help
From: Nathan Mueller <nlmueller@students.wisc.edu>
Date: Mon, 30 Nov 1998 15:22:53 -0600
Delivered-To: assembly-89-outgoing@towerguard.unix.edu.sollentuna.se
In-Reply-To: <5285cf85.3663087d@aol.com>
Reply-To: assembly-89@lists.ticalc.org


>What does decrementing the pointer by a word mean?

The pointer in this case is just the address for the top of the stack.  By
decrementing it by a word you subtract 2 from it -- since the stack grows
upwords you subtract when you add.  A word takes up two bytes of RAM, a
long word 4, and a byte 1 (duh).  With a .w instruction the pointer is
decremented by 2, 4 for a .l instruction...

	--Nate

References:

Re: A89: Starting out assembly, need help

From: TurboSoft@aol.com